Modern hearing aids comprise signal processing concepts, with the aid of which audio signals can be processed not only according to the hearing ability of the respective hearing aid device wearer but also in a situation-specific fashion. To reduce the hearing effort and to increase the hearing comfort as well as the speech comprehensibility, signal processing concepts are provided which analyze noises and can adjust the signal processing to the respective noises. A distinction is herewith made inter alia between interference sound (generally ambient noises in everyday life) and useful sound (generally speech). The aim of most signal processing concepts is to achieve the best possible relationship between the useful and interference signal, in particular in order to increase the comprehensibility of speech. As the interference sound spectrum changes with each hearing situation, a standardized filtering of the interference sound is herewith not possible. Instead, special noise reduction methods are needed here, with the aid of which the incoming signals can be classified according to their interference noise part and can be individually attenuated.
Such noise reduction methods, methods based on the Wiener filter for instance, have already been used for some time in hearing devices. The signal-to-noise ratio of the input signal can herewith be improved significantly. However, a subjective improvement, in particular less hearing effort, is thus mainly achieved. It has still not been possible to achieve an objective improvement in speech comprehensibility in this way.